Related 975Check if a program exists from a Bash script276Automatic exit from bash shell script on error114How to undo the effect of “set -e” which makes bash exit immediately if any IMHO it's better to stick to a consistent method which works in other cases (and can also help with the code readability). –Dan Cornilescu Jun 13 '15 at 15:46 4 The two lines change the working directory to the name contained in $some_directory and delete the files in that directory. if [ $RESULT -eq 0 ]; then echo success else echo failed fi if [ $RESULT == 0 ]; then echo success 2 else echo failed 2 fi share|improve this answer navigate to this website

check_exit_status "$?" Arguably, this is "cheating", since it makes a copy of $? first. –magiconair Nov 2 '11 at 22:52 | show 5 more comments up vote 140 down vote What do you mean by "drop out and echo the error"? There's absolutely no grey area if you take the suggestion without unnecessarily introducing artificial nonsense. We can apply && instead to execute commands if it does exit with zero.

Bash Test Return Code

That is, the program's ability to handle situations in which something goes wrong. evaluates to a number (0, 1, etc.) which is not null. Ask Ubuntu works best with JavaScript enabled Linux Commando This blog is about the Linux Command Line Interface (CLI), with an occasional foray into GUI territory. If you look at exit codes in the context of scripts written to be used for the command line the answer is very simple.

does not change the execution of the pipe. # Only the exit status changes. # =========================================================== # # Thanks, Stťphane Chazelas and Kristopher Newsome.

#!/bin/bash COMMAND1 . . . Bash Error Code Handling case $?

no matchgrep foo /tmp/bar.txt || echo "text not found"# grep returns 0, e.g. Can I use an HSA as investment vehicle by overcontributing temporarily? Join them; it only takes a minute: Sign up Checking Bash exit status of several commands efficiently up vote 162 down vote favorite 70 Is there something similar to pipefail for The difference between a good program and a poor one is often measured in terms of the program's robustness.

Bash Check Error Code Of Last Command

Success! I know I have, many times. Bash Test Return Code Fortunately bash provides a way to run a command or function when it receives a unix signal using the¬†trap¬†command. Bash Error Code 255 If you use¬†find¬†and¬†xargs¬†together, you should use¬†-print0¬†to separate filenames with a null character rather than new lines.

I like to include the name of the program in the error message to make clear where the error is coming from. useful reference Example : test1=`sed -i "/:@/c connection.url=jdbc:oracle:thin:@$ip:1521:$dataBase" $search` valid $test1 function valid () { if $test -eq 1; then echo "OK" else echo "ERROR" fi } I already tried do that but Here is an illustration showing that if conditions may also be nested. should contain the exit status of the previous command, which should be zero for no error. Bash Error Code Of Previous Command

These two methods seem horribly long-winded and nasty to me so I'm here appealing for a more efficient method. While this is a working solution to the problem, there are more clever methods that will save us some typing. More exit codes The exit command in bash accepts integers from 0 - 255, in most cases 0 and 1 will suffice however there are other reserved exit codes that can my review here And i want to exit with the actual spd-say exit code (it may not be 0).

UNIX is a registered trademark of The Open Group. Bash Error Code 127 ls | bogus_command # bash: bogus_command: command not found echo $? # 0 # Note that the ! grep -q regex options; then printf '%s\n' 'myscript: Pattern not found!' >&2 exit 1 fi An alternative syntax is to use && and || to perform if and else tests with

RedHat tends to maintain backwards compatibility for long, which is why the init.d stuff is still there. –dragon788 Feb 13 at 16:06 add a comment| up vote 36 down vote For

How can you tell if the string is found or not? set +e command1 command2 set -e On a slightly related note, by default bash takes the error status of the last item in a pipeline, which may not be what you Notice also that you don't need to do: command1 if [ $? -ne 0 ]; then You can simply say: if ! Bash Error Code Variable Verbatim copying and distribution of this entire article is permitted in any medium, provided this copyright notice is preserved.

So what can you do about it? Unix & Linux Stack Exchange works best with JavaScript enabled Advanced Bash-Scripting Guide: PrevNextChapter 6. special variable to print the exit code of the script. get redirected here Checking the exit code will tell you.

function mytest { "[email protected]" local status=$? When was this language released? Do COB LEDs usually need electrically insulating from the heatsink? If those conditions are true, then check whether or not it has a size greater than 0. #!/bin/bash echo "Which error log are you checking today? " read answer if [

Thanks for sharing, and thanks for the above comment. share|improve this answer answered Jun 13 '15 at 15:21 Scott 3,75821328 add a comment| up vote 0 down vote To answer your direct question, no, it's not possible to keep $? In this case you'd want the user to not exist and all their files to be removed. and $_ references.

share|improve this answer answered Jun 14 '15 at 0:48 David Z 456310 @mikeserv I'm not sure I understand - are you talking about manually assigning to $? We can use something similar to: if ( set -o noclobber; echo "$$" > "$lockfile") 2> /dev/null; then trap 'rm -f "$lockfile"; exit $?' INT TERM EXIT critical-section rm -f "$lockfile" Force Microsoft Word to NEVER auto-capitalize the name of my company Modern soldiers carry axes instead of combat knives. Hot Network Questions Can filling up a 75 gallon water heater tank without opening a faucet cause damage?